I also found it annoying when I would log in it would send me an email that someone logged in.

Gmail does that sometimes too to me.

The one benefit from email hosted by Apple is that you know the service won't disappear or cease operations anytime soon, because the service is backed by one of the richest companies in the internet/IT business. So in that perspective iCloud should be ranked in the same category as Gmail, Outlook.com, Yahoo, Mail.ru, ...

I think Apple is slowly improving the service. However, I still get more unwanted messages in my iCloud inbox than for any other service (and I have or have had quite a few). What continues to bother me are occasional messages addressed to me, but seem to be genuine messages for a different customer